The Korean Peninsula extends southward from the northeast part of the Asian continental landmass. The Japanese islands of Honshū and Kyūshū are located some 200 kilometers to the southeast across the Korea Strait; the Shandong Peninsula of China lies 190 kilometers to the west. The west coast of the peninsula is bordered by the Korea Bay to the north and the Yellow Sea and Korea Strait to the south; the east coast is bordered by the Sea of Japan (East Sea). The 8,640-kilometer coastline is highly indented. Some 3,579 islands lie adjacent to the peninsula. Most of them are found along the south and west coasts.
The line between the two Korean states was the thirty-eighth parallel of latitude. After the Korean War, the Korean Demilitarized Zone (DMZ) formed the boundary between the two. The DMZ is a heavily guarded, 4,000-meter-wide strip of land that runs along the Demarcation line established by the Korean Armistice Agreement, from the east to the west coasts for a distance of 241 kilometers (238 kilometers of that line form the land boundary with North Korea).
The total land area of the peninsula, including the islands, is 223,170 square kilometers. Some 44.6 percent (98,477 square kilometers) of this total, excluding the area within the DMZ, constitutes the territory of the Republic of Korea. The combined territories of North Korea and South Korea are about the same size as the state of Minnesota. South Korea alone is about the size of Portugal or Hungary.